Multiple fuse device



y 1935- w. H. FRANK El AL 2,000,016

MULTIPLE FUSE DEVICE Filed April 19, 1953 3 Sheets-Sheet l INVENTORS. x-9 W 34 3 BY Lu-J- W y 1935; I w. H. FRANK ET A; 2,000,016-

MULTIPLE FUSE DEVICE Filed April 19,. 1933 5 Sheets-Sheet 2 INVENTORS!4U HM gMf-Jx/ BY M 81 2 2. 8 I

ATTORNEY.

y 1935- w. H. FRANK ET AL 2,000,016

MULTIPLE FUSE DEVICE Filed April 19, 1933 5 Sheets-Sheet 3 a/ f W rron 9Patented May 7, 1935 UNITED STATES 2,000,010 mourners FUSE nEvlcEWilliam 11.

son J. L.

Frank, Joseph A. Messing, and Harri- Frank, Detroit, Mich, assignors toBulldog Electric Products Company, Detroit, Mich., a corporation of WestVirginia Application April 19, 1933, Serial No. 666,786

1'! Claim.

This application relates to circuit protective devices, and particularlyto those commonly known as multiple fuse devices.

It has been proposed in the past to provide for s circuit protection, aplurality of fuses mounted on a rotatable body element so that one afteranother of the fuses may be brought into and electrically connected tothe line as a preceding fuse blows out. Hie rotating body element of thecircuit protecting device is generally made of insulating material andgenerally has barriers, etc. as considered desirable by the designer.

One principal object of the invention is to provide, as the rotatablebody element of such a device, a substantially flat wheel, including awheel proper, of insulating material having mounted thereoncircumferentially spaced, radially positioned fuses. This design of bodyelement has proven of value per se, and also in connection with circuitprotective devices of novel design which will more specifically beillustrated in other applications. these relating more specifically tomechanisms for rotating and electrically connecting in circuit the bodyelement or wheel.

Still further objects are the provision of novel details of constructionof bcdy elements of multiple fuse circuit protective devices.

A still further object is to provide a standard fuse wheel constructedso as to be adapted for use in a number of different ways, and forvarious amperages and voltages.

A still further object is to provide a fuse wheel composed principallyof insulating material having steel or other metal enclosed parts forproviding suitable tensile strength for the wheel.

A still further object is the provision of a body element of thecharacter specified which is so arranged that the gases which ariseincident to the blowing of a-fuse are expelled into explosion chambers,from where these gases are conducted, through vent passages 'to acentral large expansion chamber or exhaust manifold and then to theatmosphere. In one embodiment of the invention these vent passages havetapered ends. where they discharge into the central chamber, and inthese ends are disposed tapered plugs of suitable material, such ascement, plaster of Paris, etc. These plugs prevent the gases dischargedby one blown fuse from entering the vent connected to a chamber in whichan unblown fuse is disposed. However when a fuse blows out, the plugwhich corresponds to that fuse is itself blown out in the direction ofenlargement of the tapered vent to release the gas pressure in theexplosion chamber and in the vent connected thereto.

It will also be observed that, for all the explosion chambers of thefuses, there is provided a common exhaust manifold or expansion chamber,This eliminates the necessity of providing for each fuse, a separateexpansion chamber, and promotes economies of space, etc. Further, theexpansion chamber need not be in the replaceable part of the device,namely the wheel, but may be in the casing of the device, thenon-replaceable part. This promotes economies of space, etc. as well asof manufacturing cost, insofar as the replaceable and necessarilyinexpensive part of the device, the wheel, is concerned.

It will also be observed that the fuses are in part encased in discswhich are embossed into place so that all of the parts of the wheel willbe tightly locked in place and thus rendered immovable on the wheel,thus insuring against parts becoming misplaced and aifecting theoperation of the device, or causing short circuits, etc. The discsfurther render the wheel substantially gas tight, to insure against arcsand hot gases injuring surrounding objects or causing electricalflashovers.

It is also an object of the present invention to provide a rotating bodyupon which are positioned a number of fuses all of which are relativelyindependent, as contradistinguished from prior constructions wherein anumber of fuses are provided in the form of arms radiating from acentral hub, all formed as one piece of fuse material. In prior artconstructions, the blowing of one fuse often causes all of the fuses toblow, since they all are connected, structurally, thermally, andelectrically. In the instant construction, where the fuses arestructurally, thermally, and electrically independent, this cannotoccur.

Further, the instant fuses have wide ends, for contact making purposes,and narrow central parts, which are the fusible parts. These centralparts are 8 shaped so that their .electrical paths will be as long aspossible, consistent with their overall length being relatively small,it being observed that longer fuse paths are apt to have a smallerpercentage of variation, in electrical charasteristics, than shorterfuse paths of equivalent resistance or calibration. However, inproportioning the fuses, recognition is taken of the fact that shortfuses offer greater heat conductivity (less heat resistivity) and morenearly uniform temperature gradient than similar, but longer fuses. Inother words, the fuses are proportioned so as to balance the desire forlength of fuse path, for uniformity of characteristics, against thedesire for shortness of fuse, for thermal con ductivity.

A still further object is the provision of a novel fuse, including astrip of a suitable fuse metal, upon which is a plating of copper, thelatter having the useful function of providing a more suitable contactor terminal surface than is provided by the fuse metal, it beingobserved that copper has a higher electrical and thermal conductivitythan is possessed by the fuse metal itself.

It will further be observed that the contact part of each fuse isisolated and .shielded from the critical part of the fuse, namely thepart within the explosion chamber and which is apt to fuse on overload.This isolation and shielding prevents the heat of explosion, or thevapors thereof, from escaping from the explosion chamber, except thruthe proper vents, etc. and specifically insures them from reaching thecontact or terminal ends of the fuses.

The wheel or body element per-se is preferably made of an insulatingmaterial which has a high heat conductivity, glazed or unglazedporcelain, plain or pyrex glass, etc. having proven practical. Suchmaterials transfer heat from the fuses very rapidly and thruout theentire wheel or disc.

Further, in one embodiment, as where the expansion chambers are in thewheel itself, these chambers are loosely stuffed with a finely dividedheat absorbing material, such as gravel, fine silicates, glass wool,etc. these also providing a tortuous but free path for the escape ofgases. The use of glass wool is particularly desirable since thismaterial has high heat absorbing qualities, and acts as a deionizing orare quenching agency. Further, the material may be used to pack theexplosion chambers.

Still further objects of the invention will presently appear uponreference to the following detailed description of embodiments of thesame, which embodiments are disclosed in detail in th accompanyingdrawings.

In these drawings Fig. 1 is a transverse section as if on line l-l ofFig. 2, of one form of wheel or body.

Fig. 2 is a cutaway elevational view of the same.

Fig. 3 shows in cutaway perspective a fuse used in the embodiment ofFigs. 1 and 2.

Fig. 4 is an elevational view of the wheel of Figs. 1 and 2 to reducedscale.

Fig. 5 is a transverse section as if on lines 5-5 of Fig. 6 of a secondform of wheel or body.

Fig. 6 is a partial cutaway elevational view of the same.

Figs. 7 and 8 are transverse sections of other modified forms of wheelsor bodies.

Fig. 9 is a transverse section of still another wheel or body, as if online 9-9 of Fig. 10.

Fig. 10 is a partially cutaway elevational view of the same.

THE WHEEL ox BODY Figs. 1-4

vThe various forms of wheels or bodies and their component parts,disclosed in Figs. 1 to 10, will now be described specifically.

The wheel or body of Figs. 1 to 4 includes a fiat wheel proper ID, ofsuitable insulating material, such as porcelain, etc., provided with alarge central hole or exhaust manifold H, from which radiate outwardly anumber of equally spaced radial slots I2. In radial alinement with eachslot, and projecting from each face of the wheel is a boss I4 andbetween the slots l2 are radially inwardly projecting fingers l5. Theouter periphery of the wheel, beyond the bosses I4, is referenced l6.

Disposed in the outer end of each slot I 2 and passing from oneperipheral edge of the wheel proper, over the boss l4 on the adjacentface, and then through the slot l2, over the boss I 4 on the oppositeface of the wheel proper, and

to the adjacent peripheral edge of the wheel proper, is a fuse element11, formed from a fiat fuse strip of the form of Fig. 3. As indicated,all of the fuses are separate and independent, and relatively isolated.The terminals or contact parts of the fuse, that is to say, the ends I8, are on the faces of the wheel over the bosses I4 and are ofsubstantial and equal width, as indicated, whereas the central part IQ,of the fuse which is the part that blows on overload, is in the form ofa narrow ribbon, having 8 shaped ends, as indicated. The fuses are madefrom a strip of suitable fuse material such as zinc, alloy, etc. and arepreferably copper plated or electroplated as indicated best in Fig. 3,so that the ends I8 will have high thermal and electrical conductivity,as they engage the associated fixed contacts of the device.

Cm the faces of the wheel proper are fibre discs 20, these havingapertures 2| receiving, and through which project the bosses l4, and theportions I8 of the fuses ll thereon, and also having their outerperipheral edges projecting beyond the wheel proper periphery IGanddeformed inwardly as indicated at 22, so that adjacent peripheral edgesof the discs may be brought together and encircled by a metal ring 23 ofchannel cross-section which binds the discs, the fuses and the wheelproper, in assembly.

The channelled ring 23 may be provided with suitable indicia asindicated best in Fig. 4, corresponding to the locations and numbers ofthe fuses ll. For the wheel shown, where there are twelve pairs ofbosses and therefore twelve fuses, the ring will be numbered from i tol2, each number corresponding to one of the fuses.

As indicated in dotted lines, the edges of the apertures 2| of the fibrediscs 20 through which the bosses l4 and the fuses ll project, arenormally deflected out of the planes of the discs and during theassembly of the discs on the wheel proper, these edges are embossed orforced into the planes of the discs so that an extremely tight and rigidconnection between the discs and the wheel proper is assured. Theseedges also isolate and shield the portions l8 of the fuses from theportions I 9 thereof, for reasons previously expressed.

On the faces of the discs 20 are disposed dished metal plates 24 coveredon their outer surfaces by fibre plates 25 whose edges are turned .inover the edges of the metal plates as indicated. These plates 24 and 25are so formed that the outer edges of plates 25 engage the discs 20;their inner portions however are substantially distant from the discs 20so that a large fiat ex pansion space will be provided between each setof plates and the adjacent disc. The flexibility of the discs providesspring, pressure for facilitating assembly of the device.

The discs 20 and the plates 24-25 are centrally apertured in alignmentand through these apertures there passes a tubular hub 27 having anoutwardly directed flange 28 adapted to bear against one of the fibreplates 25. The end of the hub 21 opposite that end thereof provided withflange 28, is, in the assembly operation, peened or riveted over a plate29 which engages one of the fibre plates 25, and the rigid assembly ofthe parts is maintained by the co-operation between the plates 24-25 andthe heads 28-29 of the hub, it being observed that the central hole edge30 of each plate 25 is inwardly extruded or flanged to act as a bearingon the hub, and to insulate the adjacent plate 24 from the hub 21, thesemetal plates being completely out of contact with any other part of theassembly other than the flbre plates 2!.

The hub 21 has a vent hole 22 which connects the exhaust manifold orcentral hole ll, into which opens the explosion chambers, or slots l2,with the interior of the hub, so that gases which rise incident to theblowing of a fuse may escape from the entire wheel assembly through thehollow hub, and into expansion chambers 38 formed in the walls of thecasing 24 containing the wheel, this feature resulting in spaceeconomies, as has been previously mentioned. Also for venting purposes,the center holes II of the discs 20, through which holes pass the hub21, may be formed square as indicated, the outer diameter of the hub 21being equal to the side dimension of each squared hole I! so that afairly tight flt between the discs 20 and the hub is assured, thecorners of the squared holes 2! serving to connect the exhaust manifoldor center hole It with the expansion chambers or flat spaces between thediscs 20 and the adjacent sets of plates 24-25.

It will be observed that the fingers I! act as barriers between theexplosion chambers or slots l2, and that discs 20 bear tightly againstthese barriers to isolate the slots relatively.

It will also be observed that the assembly shown in Figs. 1 to 4 is acompact, rigid assembly whose parts are completely insulated as theyshould be, and whose only exposed metal parts, other than the hub 21 andthe ring 24 are the terminal or contact portions ii of the fuses I!which lie upon the bosses i4.

Further it will be observed that the assembly is so constructed thatsuitable venting of the explosion gases is provided through the mediumof the hub 21 and the squared holes 35 in the discs 20.

Still further it will be observed that the assembly of Figs. 1 to 4 canbe eifected economically and expeditiously, resulting in a highlysatisfactory multiple fuse body of convenient form and of so low a costthat replacement of one body by another, after the provided number offuses have been blown, is an inexpensive as well as a simple matter, aswill be more readily brought out in a later part of this specification.

F108. 5 and 6 In Figs. 5 and 6 there is shown a wheel or body resemblingthe wheel or body of Figs. 1 to 4, differing materially in thatparalleling of fuses is provided. The wheel of Figs. 5 and 6 includes awheel proper 40 having a central hole or exhaust manifold 4| providedwith radial slots or inner explosion chambers 42 projecting therefrom,

radially and outwardly. There is also provided in alignment with eachslot 42, a radial and peripheral cutout 42 and between each cutout 43and its adjacent slot 42 are the bosses 44, one each of these projectingaxially of the wheel from each face thereof.

Around the bosses are disposed the fuses 45 and 44, the fuse 45projecting from one boss through a slot 42 to the other boss, and thefuse 48 projecting from a boss 44 through the cutout 43 to the otherboss, the terminal or contact ends of the fuse 4B overlapping the endsof the fuse 45 as indicated.

In the central hole 4i there is disposed an insulating cylinder 41against which the ends of the barriers between the slots 42 bear, thecylinder closing each slot from the central hole.

On opposite faces of the wheel proper 40, are flbre discs Ill havingholes receiving the bosses and the projecting parts of the fuses 45-46and having flanged edges ii. The discs 50 also have holes 42 alignedwith the slots 42, and radially outside of the'cylinder 41. The edge llof one disc 40 overlaps and receives the edge ii of the other disc III,and the inner edge II is slightly clear of the peripheral edge of thewheel proper. Binding the periphery of the wheel and encircling theflanges ii are the annuli 54, each of which includes a metal plate "aand a flbre plate 53b enshrouding the metal plate "a. The edges of theannuli II are flanged, as indicated at 54, with one flange l4overlapping and receiving the other flange 4. Wire staples 55 are passedthrough the flanges 54 and Bi and are clinched over against theperiphery of the wheel proper to bind the discs Ill and the annuli 53 toone another, and in place, and rivets 56 are passed through the annuli53. the discs ill and holes 51 in the portions 58 of the wheel proper,between the cutouts 43.

It is observed at this time that the portions 58 continue radiallyinwardly towards the center hole 4i, and form barriers between the slots42 and cutouts 43.

The central part of the assembly includes central plates 60-4 Irespectively of metal and fibre, a hub 42 provided with a head 63 and aseparate plate 44 over which one end of the hub is riveted. The hub hasa vent hole 65 connecting the exhaust manifold or central hole 4| withthe interior of the hub.

It is observed here that the center holes of the discs Bil may besquared as shown at 68 so as to connect hole 4i with the space 6! insideof plate sets Bil-8i for venting purposes.

It is also observed that the flange 54 is provided with suitable indiciato indicate the stations or positions of the respe "ve fuses.

The construction of Figs. 5 a...l 6 provides at each station, two fuses45-48. arranged in parallel so that a parallel connection between acontact on one side of the wheel assembly and a contact on the otherside of the wheel assembly is effected, this feature permitting heavierloads to be carried than would be the case if but one fuse 45 or 48 wereused at each station.

Because of the use of two fuses, both of which may blow, the slots 42and the cutouts 43 have been provided to act as explosion chambers ateach station, it being observed that the slots 42 open indirectly andtortuously to the manifold or central hole 4| thru the holes 52, thespaces 61, the holes 66, and the hub hole 65, whereas the explosionchambers 43 open to a common race or exhaust manifold which comprisesthe clearance space between the periphery of the wheel proper and theinner flange ii of a disc 50, such clearance space being formed in part,by the provision of grooves 60 in the peripheral edges of the radialbarriers 58 between cutouts 43. It is observed that the hot gases andfuse metal vapors, emitted thru openings 52, are directed against thecool metal plates 60. This has the effect of deionizing the gases, andalso causes the hot metal vapors to deposit their metal particles uponthe plates 60. which insures against these particles being thrown intocontact with such parts of the device, as would create conductionbetween external contacts.

Figs. 7 and 8 In Fig. 7 there is shown in transverse section a wheel orbody assembly which differs from the wheel or body assembly of Fig. 1only in that between the plates IO-II (equivalents of plates 24-25 ofFig. 1) and the wheel faces are insulation discs providing laminatedinsulation constructions as superior equivalents of the fibre discs 20of Fig. 1. These insulation constructions include, for example, a pairof mica discs I2, 9. pair of asbestos discs I3 next adjacent, a pair offibre discs ll next adjacent, a second pair of mica discs next adjacent,and a second pair of asbestos discs I6 next adjacent. In other respectsthe parts are like the correspondingly referenced parts of Fig. 1.

In Fig. 8 there is shown a construction which is also similar to theconstruction of Fig. 1, but wherein the discs of Fig. 1 are replaced bysets of discs of mica 80 and asbestos 8|, and wherein the space betweenthese sets of discs, and also the space between these sets of discs andthe plates 82-83 (equivalents of plates 2425 of Fig. 1) are filled witha granular insulating and heat absorbing material, such as looselypacked gravel, coarse silicates, glass wool, etc. The discs 808I havesquared holes similar to those provided for the disc 20 of Fig. 1 sothat venting of gases from the fuses IT to the atmosphere, through thevent holes 84 in the plates 82--83 is assured, it being observed thatthe course of the gases is tortuous and is through the granularinsulation, as indicated by the arrows.

Figs. 9 and 10 In Figs. 9 and 10 there is shown a slightly differentconstruction, one wherein the wheel proper 90, is of a transparentinsulation material, such as glass. This wheel proper is provided with alarge central hole or exhaust manifold 9| from which slots 92 projectradially outwardly. In radial alignment with each of these slots is ahole 93 and separating the end of each slot with the adjacent hole 93 isa section which provides two bosses Bl, projecting from each face of the7 wheel proper. The fuse 95 is positioned over the bosses and the narrowpart 96 of the fuse projects through the wheel 90 from the boss on oneface to the bos on the other, the hole 83 acting as an explosionchamber.

Opening into each hole 93 is a vent or duct 91 which opens into theexhaust manifold or central hole 9| in an enlarging taper 98. Thistapered portion of each vent 91 normally contains a tapered'plug 99 ofcement, plaster of Paris, glass wool, etc., so constructed that it willcrumble when the plug is blown out of the tapered end of the vent by theblowing of a fuse in an explosion chamber 93, the plug material oncecrumbled, being dissipated through the clearances and through thecentral hub whose interior is in communication with the exhaustmanifold.

It is observed that these plugs act as barriers or one-way valvesbetween one explosion chamber and another so that when a fuse blows, thegases escaping from the chamber containing that fuse do not reach anyother explosion chamber containing an unblown fuse, the taper of theplug and the portion 98 preventing the plug from being blown into thevent and crumbled when any fuse other than the one associated with theplug is blown.

Each face of the wheel proper is covered with an asbestos disc I02 whoseperipheral edge is disposed in the annular corner formed between theadjacent face of the wheel proper and the overhanging edge I03 of thewheel periphery and these discs serve to close the explosion chambers 93and ducts 51 at all points. The assembly of parts is maintained by meansof rivets I04 passing through flbre enshrouded metal plates I05, thediscs I02, and the rivet holes I06 in the wheel proper.

The central part of the wheel includes a fibre enshrouded metal plateI08, similar to the plates 24-25 of Fig. 1, and also includes the usualhub I09.

It will be seen that the condition of any fuse can be observed byviewing the fuse through the annular edge of the wheel proper 90.Further, the tapered plugs 98 may be of a color contrasting with that ofthe neighboring parts of the assembly, so that the presence or absenceof one of these plugs would indicate whether or not the fuse associatedtherewith has been blown.

Now having described several embodiments and combinations, referencewill be had to the following claims for a determination of the scope ofthe invention, it being observed that the foregoing embodiments andcombinations have been chosen merely for purposes of illustration.

- We therefore claim:

1. In a multiple fuse device, a fuse carrier comprising a substantiallyflat disc-like body of insulating material, and circumferentially spacedfuses projecting thru the body from side to side thereof and havingexposed contact ends on the fiat sides of the disc-like body, the bodyhaving a plurality of explosion chambers, one for that part of each fusethat is in the body, the chambers communicating with a center hole inthe body that acts as an explosion manifold.

2. In a multiple fuse device, a fuse carrier com prising a substantiallyflat disc-like body of insulating material having thru slots connectingthe flat sides of the body, fuses having their central parts in saidslots and having exposed contact ends projecting therefrom and lying onthe flat sides of said body, the slots extending radially from a largecentral thru hole in said body.

3. In a multiple fuse device, a fuse carrier comprising a substantiallyflat disc-like body of insulating material having thru slots connectingthe flat sides of the body, fuses having their central parts in saidslots and having exposed contact ends projecting therefrom and lying onthe flat sides of said body, the slots extending radially from a largecentral thru hole in said body, and discs of insulation on the flatsides of said body and forming side closures for said slots, andretainers for said fuses.

4. In a multiple fuse device, a fuse carrier comprising a substantiallyfiat disc-like body of insulating material having thru slots connectingthe flat sides of the body, fuses having their central parts in saidslots and having exposed contact ends projecting therefrom and lying onflat sides of said body, the slots extending radially from a largecentral thru hole in said body, and discs of insulation on the flatsides of said body forming side closures for said slots and retainersfor said fuses, the contact ends of the latter being exposed thru holesin said discs.

5. In a multiple fuse device, a circular body having a central hole, twoseries of radial thru slots, one series extending outwardly from saidhole, and one series extending inwardly from the periphery of said body,fuses in said slots and having contact ends on the faces of said body,an insulating covering on the periphery of said body for enclosing saidslots and the parts of the fuses therein, the covering being clear ofthe body so that the slots of the outer series are in relativecommunication thru the annular clearance.

6. In a multiple fuse device, a body having thru slots containing fuses,insulating sheets on the faces of said body enclosing said slots andproviding walls for explosion chambers including said slots, and afilling for said chambers comprising comminuted refractory materials,providing tortuous paths for the escape of gases generated in saidchambers incident to the blowing of fuses therein.

7. In a multiple fuse device, a body having individual explosionchambers, ducts leading from said chambers to an exhaust manifold, andoneway valves in said ducts which normally seal their respectivechambers from the manifold, but which automatically open to connecttheir respective chambers to the manifold when the fuses in theirrespective chambers are blown.

8. In a multiple fuse device, a circular body having relatively isolatedcircumferentially spaced explosion chambers, fuses therein, a centralexhaust' manifold at the axis of the body, and radial ducts connectingsaid chambers to said manifold.

9. In a multiple fuse device, a fiat circular body havingcircumferentially disposed, relatively sep arated fuses on the flatsides thereof and adapted to be rotated successively into the operativestation, and refusing means disposed on opposite sides of the flat bodyand operable automatically upon the blowing of a fuse, for rotating saidbody and placing into said station the next adjacent use.

10. In a multiple fuse device, a flat circular body havingcircumferentially disposed, relatively separated fuses on the flat sidesthereof and adapted to be rotated successively into the operativestation, and refusing means disposed on opposite sides of the flat bodyand operable automatically upon the blowing of a fuse, for rotating saidbody and placing into said station the next adjacent fuse and means forlimiting the number of refusing operations that can occur automatically.

11. In a multiple fuse device, a fuse carrier comprising a substantiallyflat disc-like body of insulating material, and circumferentially spacedfuses projecting thru the body from side to side thereof and havingexposed contact ends on the flat sides of the disc-like body, the bodyhaving a plurality of explosion chambers, one for that part of each fusethat is in the body, the chambers communicating with a center hole inthe body that acts as an explosion manifold, and a hollow center-axishub rotatably supporting said disc-like body, the interior of the centerhole communicating with the interior of the hub.

12. In a multiple fuse device, a fuse carrier comprising a substantiallyfiat disc-like body of insulating material, and circumferentially spacedfuses projecting thru the body from side to side thereof and havingexposed contact ends on the flat sides of the disc-like body, the bodyhaving a plurality of explosion chambers, one for that part of each fusethat is in the body, the chambers communicating with a center hole inthe body that acts as an explosion manifold, and a hollow center-axishub rotatably supporting said disclike body, the interior of the centerhole communlcating with the interior of the hub, gases from theexplosion chambers venting thru said hub.

13. In a multiple fuse device, a fuse carrier comprising a substantiallyflat disc-like body of insulating material having thru slots connectingthe fiat sides of the body, fuses having their central parts in saidslots and having exposed contact ends projecting therefrom and lying onthe flat sides of said body, the slots extending radially from a largecenter thru hole in said body, and discs of insulation on the flat sidesof said body forming side closures for said slots and retainers for saidfuses, the edges of the discs meeting on the periphery of the body andbeing bound by a channelled ring provided with desirable indicia.

14. In a multiple fuse device, a fuse carrier comprising a substantiallyfiat disc-like body of insulating material having slots connecting theflat sides of the body, fuses having their central parts in said slotsand having exposed contact ends projecting therefrom and lying on theflat sides of said body, the body having bosses on its flat surfacesover which said contact ends are disposed so as to project beyond themajor parts of the surfaces of the body sides.

'15. In a multiple fuse device, a fuse carrier comprising asubstantially fiat disc-like body of insulating material having radialslots connecting the flat sides of the body, fuses having their centralparts in said slots and having exposed contact ends projecting therefromand lying on the flat sides of said body, the body having bosses on itsflat surfaces over which said contact ends are disposed so as to projectbeyond the major parts of the surfaces of the body sides, and discs ofinsulation on the flat sides of said body forming side closures for saidslots and retainers for said fuses, the bosses and the contact ends ofthe fuses projecting through and being exposed through holes in saiddiscs, the edges of the disc holes clamping said fuses around saidbosses and serving as barriers between the contact ends of the fuses andthe parts thereof disposed in the slots.

16. In a multiple fuse device, a circular body having a central hole,two series of radial through slots, one series extending outwardly fromsaid hole, and one series extending inwardly from the periphery of saidbody, fuses in said slots having contact ends on the faces of said body,an insulating covering on the periphery of said body for enclosing saidslots and the parts of the fuses therein, the covering being clear ofthe body so that the slots of the outer series are in relativecommunication through the annular clearance, the ends of the fuses inone series overlapping the ends of the fuses in the other series, sothat the two series of fuses are in multiple connection.

17. In a multiple fuse device, a circular body having a central hole,two series of radial through slots, one series extending outwardly fromsaid hole, and one series extending inwardly from the periphery of saidbody, fuses in said slots and having contact ends on the faces of saidbody, an insulating covering on the periphery of said body for enclosingsaid slots and the parts of the fuses therein, the covering being clearof the body so that the slots of the outer series are in relativecommunication through the annular clearance, the insulating coveringincluding discs on the faces of said body enclosing both series of slotsand confining therein both series of fuses.

WILLIAM H. FRANK. JOSEPH A. MESSING. HARRISON J. L.

